Thursday 23 August 2012

RAINFOREST STRUCTURE

Rainforests have four distinct layers. These layers have formed based on the light available to plants which they need for photosynthesis.
These layers are:
·         The emergent layer - these trees (emergents) have broken through the canopy layer, growing taller than most trees in the battle for light. These trees can reach 50-60m in height and have trunk circumferences that can measure up to 5m. These trunks are usually supported by buttress roots, which also help protect the trees from strong winds. These trees are exposed to greater climatic and weather conditions than the other layers due to their exposure and therefore their leaves tend to be thick and waxy and hold water. Being above the other layers allows the trees to make good use of the wind to disperse seeds and fruits. This layer supports wildlife such as eagles, monkeys, butterflies, bats and snakes.

·         The canopy - also known as the primary layer. Emergents grow up to 45m. This layer can block 80% of the light reaching the under-layers of the rainforest creating high competition among many plant species. However the canopy also acts as a shield, blocking heaving rain from destroying the plants below. Thick, woody vines can be found in this layer, known as lianas, which grow up trees in the search for sunlight. In the canopy animals such as monkeys, sloths, bats, treefrogs, ants, beetles, parrots and other bird species can be found here.

·         The under canopy – also can be referred to as the ‘under-story’. This layer only receives around 2-5% of the sunlight available to the canopy. The plants that grow in this layer have adapted to make use of the little light they receive by having dark green leaves that take in more light than lighter leaves, in other words they are ‘solar collecting’ leaves. These plants also refrain from growing flowers to conserve more energy. Plant pollination is much harder on this layer due to the lack of air movement. Animals such as snakes, parakeets, leopards, jaguars and a range of insects can be found here.
Rainforest structure
·        The shrub layer – this is the forest floor and very few plants grow on this layer due to it only receiving between 0-2% of the sunlight and has 100% humidity. This layer hosts rapid decomposition of vegetation and other organisms that are broken down into nutrients that are recycled back into the rainforest. Insects, cockroaches, beetles, centipedes, millipedes and earthworms can be found here among mosses, herbs and fungi.



The BBC Learning zone website provides a video and teaching tips
when covering the rinforest structure in the classroom. See:
ttp://www.bbc.co.uk/learningzone/clips/rainforest-structure-layering/3092.html


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1 comment:

  1. I really like the links toothed web pages you put in at the end of posts. Again, you could think about how a blog with links might be used by you for setting and giving extra information for homeworks.

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